Packaging for liquid products

ABSTRACT

A package for a liquid, to be dissolved or dispersed in water, contained in an envelope of water soluble or dispersible material, the envelope having a flexible wall and a water soluble or water dispersible heat seal.

This is a continuation of application Ser. No. 07/623,944, filed on Feb.14, 1991, now abandoned.

This invention relates to a package comprising a liquid chemical or achemical dissolved or dispersed in an organic liquid contained in anenvelope of water soluble or water dispersible material and having awater soluble or water dispersible seal.

Chemicals such as pesticides and herbicides and other potentiallyharmful materials are often produced as a concentrated solution ordispersion in an organic liquid. Such chemicals are typically suppliedin a metal or blow-moulded plastics container with a screw closure. Touse the chemical pesticides or herbicides a quantity of the concentratedmaterial is measured out of the container and then mixed with a largevolume of water before being sprayed onto a locus to be treated or ontoplants. Such concentrated chemical solutions are usually highly toxic sogreat care must be taken in measuring and mixing them to avoid splashingthe liquid chemical and to avoid human or animal contact with theconcentrated solution or dispersion.

Efforts have been devoted to the design of containers to minimise therisk of accidental spillage or splashing when their contents are usedand also to reduce liquid residues remaining in the containers afteruse. Plastics containers with wide necks to facilitate pouring of theirliquid contents have been used. Blow moulded plastics containers havinghollow handles have been made in which the hollow handles are isolatedfrom the body of the container to avoid retention of liquid in thehandle.

Nevertheless, with present packages it is relatively easy to spill thecontents during the mixing process with the resulting risk ofcontamination of the environment and risk of contact with humans andanimals. Also, it is rare to empty the container and farmers, and otherusers, tend to have partly full containers left around. These representa further hazard. Even when all of the contents have been used it isdifficult to dispose of the empty container. It is also difficult towash adequately the containers and measuring instruments in which theconcentrated solutions or dispersions are handled. These devicesrepresent a further hazard to personnel and to the environment.

It has also been proposed to package agricultural chemicals in acontainer comprising a screw fitting adapted to screw onto acorresponding fitting on a spray tank. The contents of the containershould be released only when a liquid-tight seal exists between the tankand the container. Practical difficulties exist in securing widespreaduse of such a system in view of the need for standardisation of screwfitting sizes and the possibility of leakage if a liquid-tight seal isnot achieved.

It has also been proposed to package solid chemicals in water solublecontainers but such containers are normally full and no particulardifficulties arise in their production or in their use.

It has also been proposed to package chemicals in a water solublecontainer which releases the packaged chemical only after contact withwater. Such proposals have not been adopted in practice for liquidchemicals because of the limitations of known water soluble containers.Such containers have been too prone to rupture if they containedsubstantial quantities of liquid. It has also proved difficult to avoidpinholes at heat-sealed joints in the container and unacceptableweakness in the material of the container adjacent to heat sealedjoints.

Heat sealing methods heretofore used to heat seal water soluble or waterdispersible materials have not produced containers capable of retainingliquids and of withstanding the abuse to which the containers are likelyto be subjected during filling, handling and storage. It has now beendiscovered that if the envelope material is heat sealed to yield a watersoluble or water dispersible heat seal containers are obtained whichpossess improved abuse resistance for use in the storage of liquids.

Water insolubility or lack of water dispersibility in the material of aheat seal can arise when, for example, the heat sealing temperature istoo high or the dwell time of the sealing jaws is too long. Chemicaldegradation of the material being sealed can then arise. Such chemicaldegradation which is associated with, for example, increasedcross-linking of an envelope material such as PVA reduces watersolubility or water dispersibility of the material. This effect isassociated with reduced abuse resistance of the containers and rendersthem unsuitable for liquids.

The present invention seeks to overcome the disadvantages of knownpackages and to provide a package which contains e.g. a non-aqueousliquid and has one or more of the following advantageous features:

The packaged chemical is released only after contact with water in whichit is to be dissolved or dispersed, minimising the possibility ofaccidental contact of the undiluted material with the environment orwith humans or animals.

The chemical can be provided in unit dosage form suitable for dilutionwith a predetermined amount of water removing the need for undilutedchemical to be measured out.

The packaged chemical is easy to use: the packaged chemical can besimply placed in water prior to use of the chemicals.

The need for washing out of residual chemical from containers to renderthem safe for disposal is removed. Containers which have been in contactwith the packaged chemical remain uncontaminated which facilitates theirdisposal.

The envelope including the heat seal is water soluble or waterdispersible so that no insoluble residue remains to clog or interferewith equipment such as filters or spray nozzles.

The present invention accordingly provides a package which comprises anenvelope which comprises a water soluble or water dispersible materialwhich envelope comprises a flexible wall which is water soluble or waterdispersible and a water soluble or water dispersible heat seal. Thepackage preferably contains a liquid more preferably an organic liquid.

The present invention also provides a package for a liquid which is achemical or a solution or dispersion in an organic liquid of a chemicalwhich liquid is contained in an envelope which comprises a water solubleor water dispersible material which is insoluble and not dispersible inthe liquid and which envelope comprises a flexible wall which is watersoluble or water dispersible and a water soluble or water dispersibleheat seal.

It will be understood that liquid or solid chemicals can be dispersed inthe organic liquid: the dispersion can be, for example, an emulsion or asuspension.

The envelope containing the chemical is preferably only partly full sothat the envelope comprises an air space which generally occupies from 2to 40% preferably from 4% to 10%, of the volume of the envelope. Alarger space could be used but is less likely to be commerciallyattractive. Partial filling of the envelope reduces the risk of ruptureof the envelope if it is subjected to shock and reduces the risk ofrupture or leakage in the event of an increase in temperature whichmight make the bag swell or sweat.

The volume of chemical is preferably from a half liter to two liters: ahalf liter is especially preferred.

Such packaging avoids the above difficulties of the prior art. To usethe package an appropriate quantity of water is measured out into avessel such as a sprayer tank and then the envelope, e.g. a bag orsachet, is removed, e.g. tipped, from the container and placed wholeinto the vessel with a predetermined measure of water and mixed. Thecontents of the envelope are released when the material from which e.g.a bag or sachet is made dissolves or disperses throughout the watertogether with the chemical. Thus, there is no possibility of spillinge.g. the chemical liquid since it is still in the form of a closed andsealed package when it is mixed with the large volume of water. Duringmixing any splashing that occurs is splashing only of a diluted chemicaland this is naturally not so toxic to personnel or so damaging to theenvironment should any splashing or spillage occur.

The chemicals which may be packaged include those which are potentiallytoxic or damaging or detrimental to health or to the environment. Theyinclude pesticides for example fungicities, insecticides or herbicides(for example hydroxybenzonitrile herbicides, e.g. bromoxynil or ioxynilor derivatives thereof such as the salts or esters, e.g. heptanoates oroctanoates) and, more generally, chemicals which are to be dissolved ordispersed in a large volume of water or aqueous liquid, such ascompounds, e.g. metronidazole, used to combat spoilage in industrialaqueous liquids, or compounds for addition to the aqueous circuits ofe.g. domestic or industrial heating systems, compounds for addition toswimming pools, photographic materials, inks, dyestuffs, non-aqueousorganic acids and cement additives. The pesticides include, e.g.molluscicicles for addition to, for example, ponds or streams. When theenvelope material is a PVA borates, chlorides and chlorates shouldgenerally not be present in the packaged liquid in amounts effective tolead to deterioration of the envelope material or that material shouldbe protected from them.

Suitable water soluble or dispersible materials which are insoluble inthe organic solvents used to dissolve or disperse the chemical includepolyethylene oxide or methyl cellulose, but preferably the envelope,e.g. a bag or sachet, comprises polyvinyl alcohol film, i.e. partiallyor fully alcoholysed or hydrolysed e.g. 40-99%, preferably 70-92%alcoholysed or hydrolysed, polyvinyl acetate film.

The polyvinyl alcohol film may be unoriented, mono-axially oriented orbi-axially oriented. Water soluble materials are preferred. Thematerials used will generally be cold water soluble; cold water solublePVA is preferred. It will be understood that other materials may be usedwhen the packaged liquid is to be dissolved or dispersed in warm or hotwater and the heat seal itself is then soluble or dispersible in warm orhot water.

The maximum tensile strength of the material of the envelope ispreferably at least 20, more preferably from 30 to 80 N/mm² and theelongation at break is preferably 200 to 380%, more preferably from 220to 350%. Testing for these values is generally carried out at 23° C. and50% relative humidity. The thickness of the envelope material ispreferably from 10 to 500, more preferably 20 to 100 micrometers.Combinations of these physical properties are especially preferred.

The polyvinyl alcohol material may be extruded as a tube and theninflated to bi-axially orient it or, more preferably, it may be cast.When a cast film is used as is preferable, a tube is formed from thefilm and the edges heat sealed along the length of the tube. The tube issealed at one end and then filled with the desired quantity of thechemical. The tube is again sealed above the quantity of chemical toclose the envelope and form, for example, a closed bag or sachet. An airspace is preferably left above the liquid in the closed envelope and, inaddition, the combined volume of the air space and liquid is preferablyless than the maximum possible capacity of the envelope so that it isloosely filled and can flex.

The invention also provides a process for the preparation of a packageaccording to the invention which comprises heat sealing the envelopematerial to obtain a water dispersible or, preferably, a water solubleheat seal.

The heat seals in packages according to the invention are preferablymade using a sealing temperature which is generally from 140° to 220°C., preferably 160° to 180° C. The jaw pressure is generally from 1 to31/2 kg/cm², preferably 11/2 to 21/2 kg/cm². The dwell time is generally200 msec to 1.5 sec, preferably 450 msec to 1 sec.

In order to ensure optimum processability the heat sealing is generallycarried out at 15° to 25° C. and 15 to 85% relative humidity (RH). Therelative humidity is preferably 35 to 55%. Some routine experimentationmay be required to obtain suitable heat seals depending on the envelopematerial, e.g. the particular grade and the thickness of PVA chosen.Water solubility or water dispersibility of the heat seal can be checkedby direct testing for solubility or dispersibility. The quality of theseals can also be checked by visual inspection for areas of opacity orfor bubbles or, for example, by inflation of bags without liquidcontents. Imperfections in the seal may give rise to a lack of watersolubility or water dispersibility of the seal. The heat sealing processcan be carried out on conventional heat sealing equipment which permitscontrol and variation of the sealing jaw temperature, jaw pressure anddwell time.

In practice the envelopes according to the invention should releasetheir contents in less than about a minute, for example in 30 to 40seconds. It will be understood that the time taken to release thechemical will depend on a number of factors apart from the nature of thebag, including the temperature of the water and the level of agitation.

When the envelope is a bag or sachet the thickness of the walls shouldbe kept to a minimum, provided that the walls have adequate strength inorder to facilitate rapid dissolution or dispersion in water. Athickness of e.g. about 30 microns is particularly suitable, althoughlarge sachets may require thicker walls. The thicker the wall, thelonger dissolution or dispersion of the wall material will take. It willbe understood that the envelope according to the invention may comprisean area of wall which is more readily dissolved or dispersed than therest to facilitate more rapid release of the contents of the envelope.

Suitable organic liquid solvents include petroleum based solvents, e.g.petroleum ethers, mineral oils, aliphatic or aromatic hydrocarbons, e.g.hexane, octane, cyclohexane, benzene, xylene and naphthalene,halogenated aliphatic or aromatic hydrocarbons, e.g. carbontetrachloride, chloroform, methylene chloride and chlorobenzene, esterse.g. amyl acetate, ketones, e.g. cyclohexane, ethers, or a higheralcohol (lower alcohols may migrate through the water soluble or waterdispersible materials described above: this can result in productappearing on the outside of the envelope). It will be understood thatmixtures of solvents, e.g. mixtures of a hydrocarbon solvent withanother solvent, e.g. a ketone or a higher alcohol, may also be used.The organic liquid must be reasonably dry and typically contains lessthan 2 to 3% of water to ensure that it does not leak prematurely fromthe envelope.

The liquid contents of the envelope may be thickened or renderedthixotropic. An increased viscosity in the contents can reduce thelikelihood of the envelope being ruptured if the package is subjected tomechanical shock, particularly as the envelope comprises a flexiblewall. The contents of the envelope may be rendered more viscous orthixotropic by the inclusion of additives, for example, a modifiedorganophilic, or bentonite, lecithin, polymethylene oxide or silica gel.

The concentrations of pesticide or herbicide dissolved or dispersed inthe organic liquid will generally be those conventionally used: in orderto reduce the bulk of each envelope, however, concentrations may beincreased. Each envelope will preferably contain at least about 500 mland will preferably contain a convenient standard volume, for example500 ml or 1 liter, although it will be appreciated that any convenientstandard volume may be chosen. The envelope will generally contain froma quarter liter to three liters of liquid although, in particular,smaller volumes may also be packaged.

Preferably the filled envelope is packaged in an outer waterproofcontainer, for example as described in more detail in our copendingapplication entitled "Packaging for Liquids", (which relates to apackage for a liquid comprising an outer container having ashock-absorbing base and an inner water-soluble or water-dispersibleenvelope containing the liquid) which both protects the envelope fromwater and premature dissolution and also acts as a second barrierbetween the concentrated and potentially toxic liquid and personnelhandling the container and the environment. The outer container may havethe form of a container formed of plastics material with a reclosableand resealable lid containing two or more of the envelopes. Preferablyhowever each envelope is individually packed in a separate outercontainer. In this case preferably the outer container is formed ofthermoplastics material which is injection moulded or blow-moulded toform a container having a top, substantially flat flange, a side walland a base. The filled envelope is placed inside the container and thena foil lid is sealed onto the top of the substantially flat flange toprovide a completely closed and sealed outer container. The lid istypically made of aluminium foil and heat sealed onto the top flange ofthe container but it may also be made of a plastics foil or a laminateof paper, plastics and/or aluminium.

The lid is preferably sealed to the top of the container to provide agood barrier to leakage if the envelope breaks; it is preferably biggerthan the top of the container to provide a flap which can be grippedeasily to remove the lid.

A laminated lid is preferred, for example a paper/aluminium/plasticslaminate in which the plastics layer can be heat sealed to the lid toprovide a hermetic seal. The aluminium layer provides a barrier againstany pinholes which may occur in the plastics layer. The paper providesstrength, processability and a label can be printed or stuck onto it.The plastics material is preferably polyethylene terephthalate (PET)which provides a good barrier against possible leakage, has good heatsealing characteristics, allows for easy removal of the lid prior touse, does not contain halogen which is potentially damaging to theenvironment when the lid is to be disposed of, and withstands shock.Other plastics materials can also be used e.g. polyvinylidene chloride(PVDC), polyvinyl alcohol, polypropylene or nylon.

Preferably the outside of the container is printed with informationconcerning the contents of the envelope, instructions for use, and anywarnings concerning the nature and toxicity of the chemical. Thisinformation may be carried on the foil lid or on a label attached to theside wall of the outer container.

The space between the envelope and the outer container (which ispreferably at least about 5% of the volume of the container; the spacewill preferably not be more than about 30%: larger spaces could be usedbut may be less attractive commercially: about 25% is especiallypreferred. The space is preferably isolated from the atmosphere forexample by a hermetic seal on the outer container. The relative humidityin the space is preferably from 45 to 65% (about 50% being mostpreferred) at a temperature of 20° C. When the envelope material is PVAfilm the mechanical properties of the film are affected by its moisturecontent: moisture in the film is in equilibrium with moisture both inany air space inside the envelope and in any space between the envelopeand the outer container. The point of equilibrium changes withtemperature so that the film may either absorb moisture or release itduring storage. A relative humidity of 45 to 65% at 20° C. has beenfound to preserve optimum storage properties of the envelope material.

The packaging in accordance with the preferred aspects of this inventionprovides a tough, two stage packaging which provides for the safetransport of concentrated chemicals and allows handling of potentiallytoxic chemicals with the minimum risk to personnel and the environment.

The following Example illustrates the production of a package accordingto the invention having a water soluble heat seal:

EXAMPLE

PVA film was used to form bags containing a liquid herbicide by thefollowing procedure using conventional bag-making equipment.

The PVA film used was SYNTANA Type KA cold water soluble PVA film,thickness 40 micrometers, with a degree of saponification of 88 mol %.

The liquid herbicide was a mixture of bromoxynil and ioxynil esters insolution in a naphthalene solvent. The liquid contained less than 3%water.

An open-topped bag was produced from the PVA film by forming the filmaround a shoulder and then heat sealing simultaneously the bottom andside of the bag. A jaw pressure of 2 kg/cm² was used, with a jawtemperature of 160° C. and a dwell time of 1 second. The ambienttemperature was 18° C. and the relative humidity 35%.

500 ml of liquid herbicide was then dispensed into the bag the top ofwhich was then sealed leaving an air space of 4 to 5% volume within thebag. Each bag was 120 mm by 205 mm and 10 bags per minute were produced.

Each filled bag was heat sealed at the top after dispensing of theliquid leaving an air space of 4 to 5% of the bag volume, the bag beingabout 80% full of liquid. The bag is therefore both incompletely filledand has an air space above the liquid.

Each bag was then placed into a container as illustrated in theaccompanying drawings. The container material was polypropylene. Eachcontainer was sealed using a laminated top comprising PET (polyethyleneterephthalate), aluminium and paper layers. The PET layer was heatsealed to the top flange of the container leaving an air space betweenthe bag and the container. The relative humidity in the air space was50% at 20° C.

A further example of a package in accordance with this invention willnow be described by reference to the accompanying drawings, in which:

FIG. 1 is a side elevation of the complete package;

FIG. 2 is an underneath view of the outer container; and

FIG. 3 shows half of a longitudinal radial section through the completepackage.

The package comprises an outer container 1 having a foil lid 2surrounding and enclosing an envelope (a bag or sachet) 3. The bag orsachet 3 is made of cold water soluble grade oriented polyvinyl alcoholfilm 4 made from 88% alcoholysed polyvinyl acetate having a wallthickness of 30 microns which is heat-sealed into the form of a sachetcontaining 500 milliliters of a concentrated dispersion 5 of a chemicalin an organic liquid. The sachet 3 is housed inside the container 1which includes a substantially flat top flange 6 connected by uppercollar portion 7 to a tapering side wall 8. The container 1 alsoincludes a foot 9 which is joined to the lowest end of the side wall 8by a shock absorbing section 10. The container has an approximatelyrectangular cross-section with rounded corners between adjacent sidesand with outwardly bowed faces as shown most clearly in FIG. 2. Therectangular shape of the container allows relatively efficient packingtogether of a number of containers. The container is also tapereddownwardly as shown in FIG. 1, in this case by 3° to 4° from vertical,and this allows a number of containers to be nested together when emptyfor easy storage or disposal. The taper also means that the sachet issupported by the walls of the container against downward movement. Thecontainer 1 is injection moulded from a block polymer polypropylenehaving a high melt flow index and typically having a constant wallthickness throughout of, for example, substantially one millimeter. Thecontainer is made to be translucent so that, as described below, leakageof the sachet can be detected without opening the container. In analtemative embodiment the foot only can be made translucent so thatleakage can be seen. Further, polypropylene is water repellent and thismakes washing of the container easier. The material from which thecontainer is made, in this embodiment polypropylene, is sufficientlyrigid to support and protect the sachet but also has a degree offlexibility which helps absorb shocks or blows to the package.

The shock absorbing section 10 is corrugated being S-shaped incross-section as shown in FIG. 3 the ratio of the length of the sectionto its thickness being about 9:1, this ratio being chosen to allow thedesired amount of flexing having regard to the flexibility of thematerial from which it is formed.

The corrugated section forms generally transverse connection joining thelower edge of the side wall 8 to the upper edge of the foot 9 which iscapable of flexing as a result of the natural resilience of thethermo-plastics material to allow some relative upwards and downwardsmovement to occur between the foot 9 and the side wall 8. This flexingabsorbs shock loads applied to the container 1 for instance if it isinadvertently dropped, e.g. during transport or handling. Duringtransport of the packages any outer packaging containing an array ofsuch packages may be dropped or at least suffer substantial shock loadsas it is transported by, for example, lorry, or even when it is liftedand lowered by, for example, a fork lift truck. The shock absorbingportion formed between the foot and the side wall of the containerflexes and absorbs such shock loads and this partly cushions the loadsapplied to the envelope and ensures that the outer container does notsplit under the application of such a shock load. Equally, after thepackage has been removed from any outer container the shock absorberabsorbs loads if the package is, inadvertently, dropped onto a solidfloor just before it is opened to gain access to the envelope.Typically, if the package falls on its foot the shock absorbing sectionabsorbs any shock load so imposed on the container. Equally, if thecontainer falls on its side wall the rounded nature of the side wallmeans that the side wall can flex and again absorb any shock loads.Further, if the container lands upon its top flange this tends also toflex to absorb the shock load.

As can be seen from FIG. 2 the foot 9 is formed with a raised centralsection surrounded by trough 11. The trough is provided to collect anyliquid which accidently leaks from the sachet before use. As thecontainer, or at least this part of it, is translucent it is possiblefor the user to look at the foot and see whether the sachet has leakedbefore opening the container. Thus accidental contact with leakedcontents can be avoided. As will be appreciated from FIG. 2 the raisedcontrol portion of the foot leaves a space underneath it which, when thecontainer is stood on a shelf, would form a closed cavity. This couldcause problems because if the sachet does leak into the container thenvapour from the concentrate could pass through the container materialinto the cavity where it would be trapped and could attack the shelf orany coating on the shelf. Thus, to allow ventilation of this cavity theunderside of the trough 11 is formed with at least one recess or groove(not shown) directed radially of the foot.

In this embodiment the corrugated section 10 also provides an internalannular shoulder to the container upon which the sachet rests. The curveof the corrugation provides a smooth surface which will not strain orpuncture the sachet. The sachet is thus supported above the bottom ofthe container resulting in further isolation from mechanical shock. Thesachet can also flex under stress into the space to absorb shock.

The interior of the container is deliberately made to be smooth so as toallow the sachet to slide easily out of the container for use.

The sachet 3 is held inside the container 1 by the foil lid 2 which isheat-sealed onto the flange 6 of the container 1 or which mayalternatively be connected by an adhesive.

The foil lid 2 in this embodiment is made from a heat sealable laminatedmaterial such as a polyethylene terephthalate/aluminium/paper laminateand is larger than the external diameter of the flange 6 to leave alarge flap around the container which can be used to tear-off the lid.

The outer container 1 and lid 2 provide protection for the sachet 3 andso protect it from contact with water and hence its prematuredissolution. It also provides an additional barrier layer around theconcentrate 5 inside the bag or sachet 3 to provide an additionalbarrier in case of rupture of the bag or sachet 3 which prevents thepotentially harmful chemical 5 from contact with personnel or theenvironment. However, to use the concentrate, the foil lid 2 is simplyremoved and then the sachet, still sealed, is dropped into a sprayertank containing a predetermined amount of water. The material 4 of thebag or sachet dissolves rapidly in the water so allowing the contents 5to be dispersed throughout the water in the sprayer tank on mixing. Theouter container 1 is not contaminated with the concentrated chemical andcan thus be disposed of without taking any special precautions and thepersonnel dealing with the concentrated chemical never come into contactwith it, so reducing the hazards and risks involved in handling suchpotentially harmful materials.

We claim:
 1. A cold water soluble sealed envelope containing anon-aqueous liquid, said liquid comprising an agrochemical, said sealedenvelope being made by a method comprising the steps of:a) selecting awater soluble open top envelope having a flexible wall which isinsoluble in the liquid; b) introducing the non-aqueous liquid into theopen top envelope; and c) sealing the open top envelope containing thenon-aqueous liquid at a relative humidity of from about 15-85% and at asealing temperature, dwell time and sealing pressure effective toprovide a seal which is cold water soluble; and wherein the envelope andseal are capable of withstanding abuse to which the envelope and sealmay be subjected during filling, handling or storage.
 2. A sealedenvelope according to claim 1, wherein sealing is carried out at ahumidity of between about 35 and 55%.
 3. A sealed envelope according toclaim 1, wherein a total capacity of the package is greater than a totalvolume of liquid and air in the package.
 4. A sealed envelope accordingto claim 1, wherein the package seal is inspected after sealing and thepackage discarded if there are any visible imperfections.
 5. A packagecomprising a non-water soluble outer container containing the sealedenvelope according to claim
 1. 6. A package according to claim 5,wherein the outer container is a flexible polymer.
 7. A packageaccording to claim 5, wherein the outer container is a rigid polymer. 8.A sealed envelope according to claim 2, wherein the sealing is conductedat constant humidity.
 9. A sealed envelope according to claim 1, whereinthe liquid has been thickened or rendered thixotropic by inclusion of anadditive.
 10. A package according to claim 1 wherein the liquidcomprises a pesticide.
 11. A package according to claim 1 wherein theliquid comprises a herbicide.
 12. A package according to claim 1 whereinthe liquid comprises a fungicide.
 13. A package according to claim 1wherein the liquid comprises an insecticide.
 14. A package according toclaims 10, 11, 12, 13, 1 or 2 wherein the liquid is a solution,dispersion, suspension or emulsion in an organic liquid solvent andwherein the envelope is insoluble and not dispersible in the organicliquid.
 15. A package according to claim 14 in which the organic liquidcomprises a petroleum based solvent, a mineral oil, and aliphatic oraromatic hydrocarbon, a halogenated aliphatic or aromatic hydrocarbon,an ester, a ketone, an ether or a higher alcohol.
 16. A packageaccording to claim 1 wherein the envelope is made of a material having amaximum tensile strength of at least 20 N/mm² and an elongation at breakof from 200 to 380%.
 17. A package according to claim 1 wherein theenvelope is made of a material having a maximum tensile strength of from30 to 80 N/mm² and an elongation at break of from 220 to 350%.
 18. Asealed envelope according to claim 1 in which the envelope is made froma material which comprises polyethylene oxide or methyl cellulose.
 19. Aseal envelope according to claim 1 in which the envelope is made from amaterial which comprises polyvinyl alcohol.
 20. A seal envelope packageaccording to claim 1 wherein the sealing temperature is from 140° to220° C.
 21. A seal envelope according to claim 1 wherein the sealing jawpressure is from 1 to 31/2 Kg/cm².
 22. A seal envelope according toclaim 1 wherein the sealing dwell time is 200 m/sec to 1.5 sec.